Magnetic Particle Inspection (MT)

Magnetic particle inspection, sometimes called MT, MPI, or mag particle, is a nondestructive test method used to check for surface and sub-surface discontinuities and defects. The process puts a magnetic field into the part and the piece is magnetized by direct or indirect magnetization. 

Because this method relies on a magnetic field to produce results, it works best on ferrous materials, like nickel, iron, cobalt, and some alloys. Components like billets, bars, castings, forgings, fasteners, weldments and extrusions are also commonly tested using magnetic particle inspection.

Wet vs. dry inspection methods

Magnetic particle inspection can be performed using a wet or dry method, depending on the application. In both methods, the product is electrically charged to create a magnetic field. Then, Ferrous iron particles are applied to the part in a dry or in a wet suspension. If there is a crack or other defect present, the particles will be attracted to the defect. The particles will build up around the leakage and form an "indication." The indication is evaluated to determine its characteristics, its cause, and how to proceed. This allows Element’s technicians to understand the type and severity of any discontinuities on the part.

Element's ASNT-certified non destructive testing experts

Element non destructive testing inspectors are certified to American Society of Nondestructive Testing (ASNT) Level III and Level II. By examining the nature, location, and extent of an indication, our highly trained and experienced inspectors can determine the origin and cause of both surface and near-surface discontinuities. Element operates full-service non destructive testing and magnetic particle inspection labs that utilize a variety of advanced equipment capable of performing quality inspections for virtually any form of ferrous material, component, or assembly.